Pregnant need help?!?

Please help! Ive found that I have Around a thirty day cycle and I had my last period May 14th 2011 and should have gotten it on or around the 11th. (23 days from the day i ended my last period.) i ovulated around the 29th of may. Ive been so tired lately, the other day i slept for 5 hours mid day. (I never take naps.) And im just not hungry at all. I have to force myself to eat. I feel sick off and on and almost threw up the morning of the 13th. Im gassy a lot more than usually and get dizzy every now and then. I just feel bad. Me and my Fiancee want a baby so bad. I took a Clear blue pregnancy test and it was negative :( im around 19 dpo (so i figure.. not sure.. i used a calculator i found online..) so I just took another test and it was still neg. :'( yesterday I noticed when I wiped I saw a pink smudge.. like a watery type blood if you will. Other than that I havnt bleed or spotted at all. every now and then ill get a little slight cramp on the left side and it will go away. im so lightheaded and worn out. Is this my month? But why am i not getting a positive on a home pregnancy test. If I am pregnant I guess I would be bout six weeks. Has anyone experienced this and been pregnant and got - on home tests? im desperate i need help!!!